VIC-20 Kernel Project

From: Brett <danjo_at_xnet.com>
Date: Sun Jul 27 14:13:00 1997

On Sun, 27 Jul 1997, Richard A. Cini, Jr. wrote:
> On Fri, 25 Jul 1997 15:51:33 -0400, Gil Parrish wrote:
> > For the last two years, I have been working on making a
> > recompilable version of the VIC-20 Kernel ROM.<
>
> >> OK, I'm not afraid to ask the amateur question: Why?
> >> I'd love to see someone with good programming skills write some
> >> sophisticated software for the VIC-20, likely requiring at least a
> >> 16K expander or something. If your project will help lead to that,
> >> I'm all for it.
[snip]
> So...I wanted to re-learn 6502 ML and the VIC/CBM architecture. I thought
> that documenting the VIC Kernel (some thing that I had never seen in print)
> would be a nice project. Also, I thought that it sould be good to have
> recompilable Kernel code, if I ever needed to recompile it. Documenting the
> Kernel enables the programmer to understand what's in the "black box."
> This is why Andrew Shulman and Matt Pietrek have made a fortune in books
> detailing the internals of Windows.

You are right Richard. It is one thing to read the code and another to
modify it. I started on the KIM-1 board (even tho the ROMs are fully
documented in the manuals - only to find - they didn't quite match up
(it was a change to the good tho 8-) Then I did the same with my VIM-1
board and as it also contains the BASIC ROM - I did it to that one too 8-)
Actually, I wrote a 6502 2-pass assembler with Macro extenstions just to
play around with it 8-) And as soon as my AIM-65 comes in from that guy
I can't mention who sold them all - lock stock and barrel to some one else
- and is an Engineer - therefore closer to God that the rest of us. Of
course this "pure speculation" and is simply "a lie" and I regret that
I have to "insinuate" this statement.

The 6502 assembler is written in Perl - and about as fast as a sloth - it
still works well and outputs Intel HEX code and my own. I am working on
having it also output Motorola 'S' records but haven't done much with it
lately.

To really S T R E T C H myself, I also wrote a 6502 hardware emulator in
Perl that uses Sockets to act like parts of the hardware. This all runs
fine under Linux so I have found out the hardware emulator is a little
harder to work that I thought. If anybody wants to look at it or get a
copy - I could put it up on the FTP site. You will have to get your own
copies of the ROMs tho. Unless someone can verify the legal status of the
copyrights on the ROMs. I am a little busy setting up Rescue trips to dig
much further into THAT moras of mumbo-jumbo.

BC
Received on Sun Jul 27 1997 - 14:13:00 BST